Textile Industry Sector Notebook Project...Textile Industry Sector Notebook Project This report is one in a series of volumes published by the U.S. Environmental Protection Agency

Sector Notebook Project Textile Industry

EPN3 10-R-97-009

EPA Office of Compliance Sector Notebook Project:

Profile of the Textile Industry

September 1997

OEce of Compliance Office of Enforcement and Compliance Assurance

U.S. Environmental Protection Agency 401 M St., SW

Washington, DC 20460

,

Textile Industry Sector Notebook Project

This report is one in a series of volumes published by the U.S. Environmental Protection Agency (EPA) to provide information of general. interest regarding environmental issues associated with specific industrial sectors. The documents were developed under contract by Abt Associates (Cambridge, MA), Science.Applications International Corporation (McLean, VA), and Booz-Allen & Hamilton, Inc. (McLean, VA). This publication may be purchased from the Superintendent of Documents, U.S. Government Printing Office. Alisting ofavailable SectorNotebooks anddocument numbers is included on the following page.

' .

All telephone orders should be directed to:

Superintendent of Documents U.S. Government Printing Office Washington, DC 20402 (202) 512-1800

R O O a.m. to 4:30 p.m., EST, M-F FAX (202) 512-2250

Using the form provided a t the end of this document, all mail orders should be directed to:

U.S. Goveimnent Printing Office P.O. Box 371954 Pittsburgh, PA 15250-7954

Complimentary volumes are available to certain'groups or subscribers, such as public and academic libraries, Federal, State, and local governments, and the media from EPA's National Center for Environmental Publications and Information at (800) 490-9198. For further information, and for answers to questions pertaining to these documents, please refer to the contact names and numbers provided within this volume.

Electronic versions ofall Sector Notebooks are available free ofcharge at the following web address: www.epa.gov/oecdsector. Direct technical questions to the "Feedback" buttonat the bottom ofthe web page.

Cover photograph courtesy of American Textile Manufacturers Institute.

Sector Notebook Project I1 September 1997


Sector Notebook Contacts

The Sector Notebooks were developed by the EPA's Ofice of Compliance. Questions relating to the Sector Notebook Project can be directed to:

Seth Heminway, Coordinator, Sector Notebook Project US EPA Ofice of Compliance 401 M St., SW (2223-A) Washington, DC 20460 (202) 564-7017

Questions andcommentsregardingtheindividual documents canbedirectedto the appropriate specialists listed below.

Document Number EPN310-R-95-001. EPN3 10-R-95-002. EPAI3 10-R-95-003. EPN3 10-R-95-004. EPN3 10-R-95-005. EPN3 IO-R-95-006. EPN3 IO-R-95-007. EPN3 IO-R-95-008. EPN3 IO-R-95-009. EPN3 IO-R-95-0 IO. EPN3IO-R-95-OII.- EPN3 IO-R-95-012. EPN3 IO-R-95-0 13. EPN3 IO-R-95-014. EPN310-R-95-015. EPN3 10-R-95-016. EPN310-R-95-017. EPN3 10-R-95-018. EPN3 IO-R-97-001. EPN3 IO-R-97-002. EPN3 IO-R-97-003. EPN3 IO-R-97.004. EPN3 IO-R-97-005. EPN3 IO-R-97-006: EPN3 IO-R-97-007. EPN3 IO-R-97-008. EPN3 10-R-97-009. EPN3 10-R-97-010, EPN3 IO-R-98-001 EPN3 IO-R-98-002.

EPN3 IO-R-98-003. EPN3 IO-R-98-004. EPN3 10-R-98-005.

EPN3 10-R-98-008

Industry Dry Cleaning Industry Electronics and Computer Industry* Wood Furniture and Fixtures Industry Inorganic Chemical Industry* Iron and Steel Industry Lumber and Wood Products Industry Fabricated Metal Products Industry' Metal Mining Industry Motor Vehicle Assembly Industry Nonferrous Metals Industry Non-Fuel, Non-Metal Mining Industry Organic Chemical Industry* Petroleum Refining Industry Printing Industry Pulp and Paper Industry Rubber and Plastic Industry Stone, Clay, Glass, and Concrete Industry Transportation Equipment Cleaning Ind. Air Transportation Industry Ground Transportation Industry Water Transportation Industry Metal Casting Industry Pharmaceuticals Industry Plastic Resin and Man-made Fiber Ind. Fossil Fuel Electric Power Generation Ind Shipbuilding and Repair Industry Textile Industry Sector Notebook Data Refresh-1997 Aerospace Industry ' Agricultural Chemical, Pesticide, and Fertilizer Industry Agricultural Crop Production Industry Agricultural Livestock Production Ind. Oil and Gas Exploration and Production Industry Local Government Operations

'Spanish translations available.

Contact Joyce Chandler Steve Hoover Bob Marshall Walter DeRieux Maria Malave Seth Heminway Scott Throwe Jane Engert Anthony Raia Jane Engert Rob Lischinsky Walter DeRieux Tom Ripp Ginger Gotliffe Seth Heminway Maria Malave Scott Throwe Virginia Lathrop Virginia Lathrop Virginia Lathrop Virginia Lathrop Jane Engert Emily Chow Sally Sasnett Rafael Sanchez Anthonv Raia

Phone (202) 564-7073 564-7007 564-7021 564-7067 564-7027 564-7017 564-7013 564-5021 564-6045 564-502 1 564-2628 564-7067 564-7003 564-7072 564-7017 564-7027 564-7013 564-7057 564-7057 564-7057 564-7057 564-5021 564-7071 564-7074 564-7028 564-6045

Belinda Breidenbach 564-7022 Seth Heminway 564-7017 Anthony Raia 564-6045 Amy Porter 564-4 149

Ginah Mortensen (913)551-7864 Ginah Mortensen (913)551-7864 Dan Chadwick 564-7054

John Dombrowski 564-7036

... Sector N o t e b o o k Project . ul September 1997

Page iv intentionally le!? blank.


TEXTILE INDUSTRY

TABLE OF CONTENTS

LISTOFFIGURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

(SIC 22)

LISTOFTABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii

LISTOFACRONYMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

. . . . . . . . . . . . . . . . . . . . . . I . INTRODUCTION TO THE SECTOR NOTEBOOK PROJECT 1 A . Summary of the Sector Notebook Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 B . Additional Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 . INTRODUCTION'TO THE TEXTILE INDUSTRY 3 A . History of the Textile Industry . . . . . . . . . . . . . . . . . . .

C . Characterization of the Textile Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 B . Introduction, Background, and Scope of the Notebook

1 . Product Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . Industry Size and Geographic Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.EconomicTrends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IO

I11 . INDUSTRIAL PROCESS DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . 13 A . Industrial Processes in the Textile Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

1 . Yam Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2 . Fabric Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3 . Wet Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

B . Raw Material Inputs and Pollution Outputs in the Production Line . . . . . . . . . . . . . 40 C . Management of Chemicals in the Production Process . . . . . . . . . . . . . . . . . . . . .

IV . CHEMICAL RELEASE AND TRANSFER PROFILE . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 A . EPA Toxic Release Inventory for the Textile Industry . . . . . . . . . . . . . . . . . . . . B . Summary of Selected Chemicals Released . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C . Other Data Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 D . Comparison ofToxic Release Inventory Between Selected Industries . . . . . . . . . . . 71

V . POLLUTION PREVENTION OPPORTUNITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 A . Quality Control for Raw Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 B . Chemical Substitution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 C . Process Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 D . Process Water Reuse and Recyc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 E . Equipment Modification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 F . Good Operating Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

Sector Notebook Project V September 1997


VI . SUMMARY OF APPLICABLE FEDERAL STATUTES AND REGULATIONS . . . . . . 89 . 89

B . Industry Specific Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 C . Pending and Proposed Regulatory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

VI1 . COMPLIANCE AND ENFORCEMENT PROFILE . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 A . Textile Industry Compliance History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111

C . Review of Major Legal Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . 118 1 . Review of Major Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 2 . Supplementary Environmental Projects (SEPs) . . . . . . . . . . . . . . . . . . . . . . 118

VI11 . COMPLIANCE ACTIVITIES AND INITIATIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 . . . . . . . . . . . . . . . . . 119

B . Trade Associatiodhdustry Sponsored Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 1 Environmental Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 2 . Summary of Trade Associations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

IX . 'CONTACTS AND REFERENCES . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

A . General Description of Major Statutes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B . Comparison of Enforcement Activity Between Selected Industries . . . . . . . . . . . . . 113

A . EPA Voluntary Programs . . . . . . . . . . . . . . . . . . . . . . .

Sector Notebook Project vi September 1997

Textile Industry I Sector Notebook Project

LIST OF FIGURES

Figure 1: Distribution of Textile Establishments in the US . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Figure 2: Typical Textile Processing Flow Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Figure 3: Yarn Formation Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Figure 4: Comparison of Open-End and Ring Spinning Methods . . . . . . . . . . . . ~ . . . . . . . . . . . 18 Figure 5: General Fabric Formation Processes Used for Producing Flat Fabrics . . . . . . . . . . . . 20 Figure 6 : Examples of Satin Weaving Patterns . . . . . . . . . . . . . . . ! . . . . . . . . . . . . . . . . . . . . . 21 Figure 7: Typical Shuttle Loom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Figure 8: Typical Air Jet Loom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Figure 9: Comparison Between Warp and Wee Knitting Methods . . . . . . . . . . . . . . . . . . . . . . 25 Figure 10: Typical Wet Processing Steps for Fabrics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Figure 11: Common Dyeing Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Figure 12: Materials Flow for a Cotton Knit Golf Shirt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Figure 13: Summary'ofTRI Releases and Transfers by Industry . . . . . . . . . . . . . . . . . . . . . . . . . 72

I .

.

Sector Notebook Project vii September 1997


LIST OF TABLES

Table 1: Standard Industrial Classifications within the Textile Industry . . . . . ; . . . . . . . . . . . . . . 5 Table 2: Summary Statistics for the Textile Industry Table 3: Summary of Establishment Sues within the Textile Industry . . . . . . . . . . . . . . . . . . . . . 7 Table 4: Top U S . Companies in the Textile Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 5: Geographic Distribution of Textile Mills in the United States . . . . . . . . . . . . . . . . . . . : . . 9

Table 7: Typical BOD Loads &om Preparation Processes Table 8: Summary of Potential Releases Emitted During Textiles Manufacturing . . . . . . . . . . 43

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 6: Typical Characteristics of Dyes Used in Textile Dyeing Operations . . . . . . . . . . . . . . 35 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 9: Source Reduction and Recycling Activity for the Textile Industry ; . . . . . . . . . . . . . . 52 Table IO: 1995 TRI Releases for Textiles Manufacturing Facilities . . . . . . . . . . . . . . . . . . . . . . 58 Table 11: 1995 TRI Transfers for Textiles Manufacturing Facilities . . . . . . . . . . . . . . . . . . . . . . 61 Table 12: Top 10 TRI Releasing Textile Manufacturing Facilities Reporting Only SIC 22 . . . . 64 Table 13: Top 10 TRI Releasing Facilities Reporting Only Textile Manufacturing SIC Codes . 65 Table 14: 1995 Criteria Air Pollutant Releases (tondyear) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Table 15: Toxics Release Inventory Data for Selected Industries . . . . . . . . . . . . . . . . . . . . . . . 73 Table 16: Typical Water Savings Using Countercurrent Washing . . . . . . . . . . . . .

. . . . . . . . . . . . 83 Table 18: Five-Year Enforcement and Compliance Summary for the Textile Industry . . . . . . 1 12 Table 19: Five-Year.Enforcement and Compliance Summary for Selected Industries . . . . . . . 114 Table 20: One-Year Enforcement and Compliance Summary for Selected Industries . . . . . . . 115 Table 21: Five-Year Inspection and Enforcement Summary by Statute for Selected Industries 116 Table 22: One-Year Inspection and Enforcement Summary by Statute for Selected'Industries 117 Table 23: Textile Industry Participation in the 33/50 Program . . . . . . . . . . . . . . . . . . . . . . . . 121

. .

Table 17: Example Costs and Savings for Dyebath Reuse . . . . . . . . . . . . .

Sector Notebook Project viii September 1997


LIST OF ACRONYMS

AFS - AIRS - BIFs - BOD - CAA - CAAA- CERCLA - CERCLIS - CFCs - co - COD - CSI - CWA - D&B - ELP - EPA - EPCRA'- FIFRA - FINDS - HAPS - HSDB - IDEA - LDR - LEPCs - MACT - MCLGS - MCLS - MEK - MSDSs - NAAQS - NAFTA - NCDB - NCP - NEIC - NESHAP - NO, - NOV - NO, - NPDES - NPL - NRC - NSPS - O A R - OECA -

AIRS Facility Subsystem (CAA database) Aerometric Information Retrieval System (CAA database) Boilers and Industrial Furnaces (RCRA) Biochemical Oxygen Demand Clean Air Act Clean Air Act Amendments of 1990 Comprehensive Environmental Response, Compensation and Liability Act CERCLA Information System Chlorofluorocarbons Carbon Monoxide Chemical Oxygen Demand Common Sense Initiative Clean Water Act Dun and Bradstreet Marketing Index ' Environmental Leadership Program United States Environmental Protection Agency Emergency Planning and Community Right-to-Know Act Federal Insecticide, Fungicide, and Rodenticide Act Facility Indexing System Hazardous Air Pollutants (CAA) Hazardous Substances Data Bank Integrated Data for Enforcement Analysis Land Disposal Restrictions (RCRA) Local Emergency Planning Committees Maximum Achievable Control Technology (CAA) Maximum Contaminant Level Goals Maximum Contaminant Levels Methyl Ethyl Ketone Material Safety Data Sheets National Ambient Air Quality Standards (CAA) North American Free Trade Agreement National Compliance Database (for TSCA, FIFRA, EPCRA) National Oil and Hazardous Substances Pollution Contingency Plan National Enforcement Investigation Center National Emission Standards for Hazardous Air Pollutants Nitrogen Dioxide Notice of.Violation Nitrogen Oxides National Pollution Discharge Elimination System (CWA) National Priorities List National Response Center New Source Performance Standards (CAA) Office of Air and Radiation Ofice of Enforcement and Compliance Assurance

Sector Notebook Project ix September 1997

~~

Textile Industry -2ctor Notebook Project

OPA - OPPTS - OSHA - osw - OSWER - ow - P2 - PCS - POTW - RCRA - RCRIS - SARA - SDWA - SEPs - SERCS - SIC - so, - so, - TOC - TRI - TRIS - TCRIS - TSCA - TSS - UIC - UST - v o c s -

Oil Pollution Act Office of Prevention, Pesticides, and Toxic Substances Occupational Safety and Health Administration Office of Solid Waste Office of Solid Waste and Emergency Response Office of Water Pollution Prevention Permit Compliance System (CWA Database) Publicly Owned Treatments Works Resouice Conservation and Recovery Act RCRA Information System Superfimd Amendments and Reauthorization Act Safe Drinking Water Act Supplementary Environmental Projects State Emergency Response Commissions Standard Industrial Classification Sulfur Dioxide Sulfur Oxides Total Organic Carbon Toxic Release Inventory Toxic Release Inventory System Toxic Chemical Release Inventory System Toxic Substances Control Act Total Suspended Solids Underground Injection Control (SDWA) Underground Storage Tanks (RCRA) Volatile Organic Compounds

Sector Notebook Project X September 1997

Textile Industry Introduction

I. INTRODUCTION TO THE SECTOR NOTEBOOK PROJECT

I.A. Summary of the Sector Notebook Project,

Integrated environmental policies based upon comprehensive analysis of air, water and land pollution are a logical supplement to traditional single-media

1 approaches to environmental protection. Environmental regulatory agencies ! are beginnimg to embrace comprehensive, multi-statute solutions to facility ' permitting, enforcement and compliance assurance, education/ outreach,

research, and regulatorydevelopment issues. The centralconcepts driving the new policy directionare that pollutant releases to eachenvironmentalmedium (air, water and land) affect each other, and that environmental strategies must actively identify and address these inter-relationships by designing policies for

i the "whole" facility. One way to achieve a whole facility focus is to design environmental policies for similar industrial facilities. By doing so,

, environmental concerns that are common to the manufacturing of similar . . products can be addressed in a comprehensive manner. Recognition of the

j need to develop the industrial "sector-based" approach within the EPA Office c of Compliance led to the creation of this document. I

> I

I The Sector Notebook Project was originally initiated by the Office of

~ Compliance within the Office of Enforcement and Compliance Assurance ' (OECA) to provide its staff and managers with summary information for

eighteen specific industrial sectors. As other EPA offices, states, the regulated community, environmental groups, and the public became interested in this

! project, the scope of the original project was expanded to its current form. I The ability to designcomprehensive, commonsense environmental protection ~ measures for specific industries is dependent on knowledge of several inter- ' related topics. For the purposes of this project, the key elements chosen for

inclusion are: general. industry information.(economic and geographic); a ~ description of industrial processes; pollution outputs; pollution prevention

opportunities; Federal statutory and regulatory framework; compliance history; and a description of partnerships that have been formed between regulatory agencies, the regulated community and the public.

For any given industry, each topic listed above could alone be the subject of , a lengthy volume. However, in order to produce a manageable document, this

project focuses on providing summary information for each topic. This I format provides the reader with a synopsis ofeach issue, and references where

more in-depth information is available. Text within each profile was researched from a variety of sources, and was usually condensed from more detailed sources pertaining to specific topics. This approach allows fora wide coverage of activities that can be further explored based upon the citations and references listed at'the end of this profile. As a check on the information. included, eachnotebook went through an external review process. The Office of Compliance appreciates the efforts of all those that participated in this

Sector Notebook Project 1 September 1997

Textile Industry . Introduction

process and enabled us to develop more complete, accurate and up-to-date summaries. Many ofthose who reviewed this notebook are listed as contacts in Section IX and may be sources of additional information. The individuals and groups on this list do not necessarily concur with all statements within this notebook.

I.B. Additional Information

Providing Comments

OECA's Ofice of Compliance plans to periodically review and update the notebooks and will make these updates .available both in hard copy and electronically. lfyou have any comments on the existing notebook, or ifyou would like to provide additional information, please send a hard copy and computer disk' to the EPA Office of Compliance, Sector Notebook Project, 401 M St., SW (2223-A), Washington, DC 20460. Comments can also be uploaded to the Environ$en$e World Wide Web for general access to allusers of the system. Follow instructions in Appendix A for accessing this system. Once you have logged in, procedures for uploading text are available fiom the on-line Enviro$en$e Help System.

Adapting Notebooks to Particular Needs

The scope ofthe industry sector described in this notebook approximates the national occurrence of facility types within the sector. In many instances, industries within specific geographic regions or states may have unique characteristics that are not fully captured in these profiles. The Office of Compliance encourages state and local environmental agencies and other

* groups to supplement or re-package the information included in this notebook to include more specific industrial and regulatory information that may be available. Additionally, interested states may want to supplement the "Summary of Applicable Federal Statutes and Regulations" section with state and local requirements. Compliance or technical assistance providers may also want to develop the "Pollution Prevention" section in more detail. Please contact the appropriate specialist listed on the opening page ofthis notebook if your office is interested in assisting us in the further development of the information or policies addressed within this volume. If you are interested in assisting in the development of new notebooks for sectors not already covered, please contact the Office of Compliance at 202-564-2395.



11. INTRODUCTION TO THE TEXTILE INDUSTRY

This sectionprovides background informationon the history, size, geographic distribution, employment, production, sales, and economic condition of the textile industry. The facilities described within the document are described in terms of their Standard Industrial Classifcation (SIC) codes.

1I.A. History of the Textile Industry

The textile industry is one of the oldest in the world. The oldest known textiles, which date back to about 5000 B.C., are scraps of linen cloth found in Egyptian caves. The industry was primarily a family and domestic one until the early part ofthe 1500s when the frst factory system was established. It wasn’t until the Industrial Revolution in England, in the 18th century, that power machines for spinning and weaving were invented. In 1769 when Richard Arkwright’s spinning frame with variable speed rollers was patented, water power replaced manual power (Neefus, 1982).

In the early 17th century of colonial America, textiles were primarily manufactured in New England homes. Flax and wool were the major fibers used, however, cotton, grown primarily on southern plantations, became increasingly important (Wilson, 1979). In 1782 Samuel Slater, who had worked as an apprentice to Arkwright’s partner, emigrated to America. In Blackstone River, Rhode Island, he started building Arkwright machines and opened the fist English-type cotton mill in America (ATMI, 1997a). In the early nineteenth century, in Lowell, Massachusetts, the frst mill in America to use power looms began operations. It was the fust time that all textile manufacturing operations had been done under the same roof (Wilson, 1979 and ATMI, 1997a).

The twentieth century has seen the development of the f is t manmade fibers (rayon was frst produced in 1910). Although natural fibers (wool, cotton, silk, and linen) are still used extensively today, they are more expensiveand are often mixed with manmade fibers such as polyester, the most widely used synthetic fiber. In addition, segments of the textile industry have become highly automated and computerized (ATMI, 1997a).

The textile industry is characterized by product specialization. Most mills only engage in one process or raw material. For example, a mill may be engaged in either broadloom weaving of cotton or broadloom weaving of wool. Similarly, many mills specialize in either spinning or weaving operations, although larger integrated mills may combine the two operations. These large mills normally do not conduct their own dyeing and f ~ s h i n g operations. Weaving, spinning, and knitting mills .usually send out their fabrics to one of the approximately 500 dyeing and f ~ s h i n g plants in the United States (EPA, 1996).



1I.B. Introduction, Background, and Scope of the Notebook

Broadly defined, the textile industry consists of establishments engaged in spinning natural and manmade fibers into yarns and threads. These are then converted (by weaving and knitting) into fabrics. Finally, the fabrics and in some cases the yarns and threads used to make them, are dyed and f ~ s h e d .

The manufacturing oftextiles is categorized by the Ofice ofManagement and Budget (OMB) under Standard Industrial Classification (SIC) code 22. The StandardIndustrial Classification system was established by OMB to track the flow of goods and services in the economy, by assigning a numeric code to these good and services. SIC 22 is categorized .into nine three-digit SIC codes. Due to the large number ofprocesses used in the textile industry and the limited scope of this notebook, the production of nonwoven synthetic materials and carpets is not discussed in detail. The primary focus of this notebook is on weaving and knitting operations, with a brief mention of processes used to make carpets.

OMB is in the process of changing the SIC code system to a system based on similar production. processes called the North American Industrial Classification System (NAICS). In the NAIC system, textile mills (including fiber, yarn and thread mills, fabric mills, and textile and fabric finishing and coating mills) be classified as NAIC 313. Textile product mil ls (including furnishings, carpets, rugs, curtains, linens, bags, canvas, rope, twine, tire cord and tire fabric) will be classified as NAIC 314.

This notebook covers the textiles industry as defmed by SIC 22. Less focus is given to SIC 229, Miscellaneous Textile Goods in the Industrial Process Descriptions Section because the processes used and products manufactured vary substantially within SIC 229. Products categorized under SIC 229 include coated fabrics, not rubberized, tire cord-and fabrics, cordage and twine, and textile goods not elsewhere.classitied. It is important to note, however, that the Miscellaneous Textile Goods category is coveredin Section 11, Introduction to the Textile Industry; Section IV, Chemical Release and Transfer Profile; Section VIII, Compliance Activities and Initiatives; and other sections ofthis document. Industry sectors related to the textiles industry, but not categorized under SIC 22 (and thus, not in the scope of this notebook) include the manufacturing of clothing and apparel (SIC 23) and the manufacturing of rubber coated textile goods (SIC 3069).

,



1I.C. Characterization of the Textile Industry

II.C.1. Product Characterization

Within the nine broad categories in the textile industry are 22 four-digit SIC codes which more narrowly defne the different types of products made by textile manufacturers. The various SIC codes and their associated products are shown in Table 1.

3-digit SIC code

SIC 221- Broadwoven Fabric Mills, Cotton

T IC 222- Broadwoven Fabric Mills, Manmade Fiber and Silk SIC 223- Broadwoven Fabric Mills, Wool

4-digit SIC Code SIC 221 1 - Broadwoven Fabric Mills, Cotton SIC 2221 - Broadwoven Fabric Mills, Manmade Fiber and Silk

SIC 223 1 - Broadwoven Fabric Mills, Wool (including dyeing (Including dwrtrg andJinishrn& 3nJ finishing)

Wool, Silk, and Manmade Fiber

SIC 225- Knitting Mil ls

SIC 226- Dyeing and Finishing Textiles, except wool fabrics and knit goods

SIC 227 - Carpets and Rugs SIC 228- Yarn and Thread Mil ls

. .

Source: Srandurd /ndit.


width.); 3) dyeing and f ~ s h i n g fibers, yarns, fabrics, and knitted goods; 4) coating, waterproofmg and treating fabrics; 5) integrated manufacture ofknit apparel and other products fiom yarn; and 6) manufacture of felt, lace, nonwoven, and other miscellaneous textile products. More detailed information on the industrial processes used to produce the various textile products is provided in Section 111.

II.C.2. Industry Size and Geographic Distribution

According to the 1992 Census of Manufacturers for SIC 22 (the most recent census data available), there were a totalof5,584 establishments in the textile manufacturing industry. A large proportion ofthese were knitting mills (SIC 225) and yam and thread mills (SIC 228), as.shown in the shaded rows in Table 2. Together these categories accounted for almost 50 percent of the total number of establishments in the industry. 'They also accounted for the largest portion of the employment and value of shipments in the textile industry. The knitting and yam and thread mills categories accounted for 46 percent ofthe 614,000people employed in the industry, and40 percent ofthe $70.5 million in value of shipments, in 1992. A summary ofthese statistics is shown in Table 2.

- Table 2: Summary Statistics for the Textile Industry (SIC 22)

Industry Establishments Companies (No.)' Employment (000's) Value of Shipments SIC Code (No.)' (millions of dollars)'

SIC 221 323 281 55.9 5,814

SIC 222 422 321 87.4 8,793

SIC 223 99 87 13.7 1.612

Totals 5,584 5,090 614 70,518

Department of Commerce, Bureau ofthe Census, 1995.

Note: The shaded rows highlight the SIC d e s which cmtain the largest number ofestablishments, employment, and value of shipmenu. 'An establishment is a phFical location where manufacturing takes place. Manufacturing is defined as the mechanical or chemical transformation of substanoes or materials into new produds. 'Defined as a business organimtion wnsisting of one establishment or more under common ownership or control. 'Value of all products andservices sold by establishments in the industry sector.

Most textile mills are small, specialized facilities. A large percentage of establishments in the industry have fewer than 20 employees, as shown in the



shaded column. The exceptions include yam and thread mills (SIC 228) and manmade fiber and silk broadwoven fabric mil ls (SIC 222), which have 100 employees or more per establishment. Some of the larger 'integrated' mil ls may employ anywhere from hundreds to thousands ofpeople. A summary of these statistics is shown in Table 3.

Sntc 'The s h h d column hi&hlightr thr. 13rgu prrcent.!pe o f i x t lmcs t h d haye fc\ver than 20 cmpluyees 'An wuhlishment IS a phpcal Ix3tinn ehGrc m.inuf3cmnng I 3 k o plxc htJnUhCNnng I, &fined as thc mcihaniwl or

The ten hrgest textile companies (in ternis of sales) in the U.S. are listed in Table 4. The data shown is taken from the Euirdiild's Trxrile & Appurel Finuncrul Directory, 1996, which compiles financial data on U.S. textile companies. Fuirchild's ranks each U.S. company by sales volume. Readers should note that ( I ) each company w3s assigned a 3- or 4-digit SIC code that most closely resembles the firm's principal industry using Wurd'r Burinerr Director?! of U.S. Private undl'uhlic Conipunicss; and ( 2 ) sales figures include those of subsidkclries and operations (cvcn those not related to textiles industry). Additional sources of company-specific financial informtion mcludc Standard and Poor's Stock Report Servicex, Dun and Bradstreet's Million Dollar Direcrory. Moody's Manuals, and the companics' annual reports. In compiling Table 4, the top compclnics for the )-digit SIC code categories in the textile industry were identified.

Sector Notebook Project I September 1997


The geographic distribution of the textile industry in the U.S. is largely governed by its history in this country. The industry began in New England and moved to the South as cotton became the primary source of fibers. The five major states for employment in the textile industry are North Carolina, Georgia, South Carolina, Alabama, and Virginia. Though the majority of mills are located in the South, northern states such as Maine, Massachusetts, New York, New Jersey, Rhode Island, and Pennsylvania are still important to the textile industry. Many finishing and dyeing (SIC 226) operations are located inNew Jersey. Narrow fabrics and manmade fiber mills (SIC 224) are more concentrated in Rhode Island and Pennsylvania. Knitting mills (SIC 225) and miscellaneous textile mills (SIC 229) are scattered through several southern and northern states. The leading states in terms of employment for the textile industry are shown by SIC code in Table 5 .

A map showing the number of textile establishments (based on census data) in each state follows the table (Figure 1).



Table 5: Geographic Distribution of Textile Mills in the United States

SIC 221

SIC 222

SIC 223

SIC 224

3-digit SIC code Major states (based on employment) approximate % of employment in 3-digit SIC code category, attributable to major II states

NC, SC, GA, AL 87

SC, NC, GA, VA 79

NC, PA, RI, SC 52 VA, GA, ME, NC 69

SIC 225

SIC 226

SIC 227

SIC 228

SIC 229

NC, KY, LA, NY, GA, PA, TX, NJ 40

NC, SC, GA, NJ 63 GA 64

NC, GA, SC 70

’ NC, SC, GA, AL, TN, MA, OH, NY 40

Figure 1: Distribution of Textile Establishments in the U.S. I

Source: 1992 Census afManufuctures, Industry Series, for SICs2211 - 2299, U.S. Department of Commerce, Bureau ofthe Census, 1995.



II.C.3. Economic Trends

Throughout the 1990s, the textile industry indicators have shown improvements. The year 1994 was a peak year for all indicators including exports, capital expenditures, employment, and mill fiber consumption. In 1994, mill fiber consumption set a record with a 6 percent increase to 16.1 billion pounds. In 1995, fiber consumption decreased by 1.7 percent only to increase by 1 percent in 1996 (ATMI,.1997b). Both 1994 and 1996 were record years for fiber consumption and were a substantial improvement over the recession years in the early part of the decade. The industry has also experienced a shifl towards increasing international trade with countries such as Canada and Mexico (ATMI, 1996).

Domestic Economy

“The textile industry spends four to six percent of sales on capital expansion and modernization, down ffom eight to ten percent during the expansionary phase of the 1960s and 1970s. Most recent capital expenditure has paid for mill modernization and factory automation” (EPA, 1996). According to the American Textile Manufacturers Institute (ATMI), the largest trade’ association for the industry, capital expenditures by domestic textile companies have increased in recent years reaching $2.9 billion in 1995 (ATMI, 1997b). The increase in capital expenditures has led to an increase in productivity. Between 1975 and 1995, loom productivity, measured in square yards of fabric per loom, increased by 267 percent and was up 10.5 percent in 1996 (ATMI, 1997b). In the same period, productivity of broadwoven fabric. mills, measured by an index of output per production employee hour, increased by 105 percent, and productivity of yarn spinning mills increased by 88 percent (ATMI, 1996). Industry also reports spending more than $25 million each year on pollution and safety controls.

“Economies of scale in textile manufacturing are significant and limit entry into the market. The cost o fa new fiber plant, for example, is approximately $100 million. Costs of raw materials are kequently volatile and typically account for 50 to 60 percent of the cost of the fmished product. To hedge against supply shocks and to secure supply, many producers are vertically integrated backward into chemical intermediates (and in the case ofcompanies such as Phillips and Amoco, all the way to crude oil). Forward integration into apparel and product manufacture (e.g. carpeting) also is not uncommon.” (US EPA;1996).

International Trade

Over the past five years, the textile industry has been increasingly influenced by international trade. In particular, with the signing of the North American Free Trade Agreement (NAFTA) in 1994, trade with Canada and Mexico has



increased significantly. In 1996, 42 percent of U.S. textile exports were to Canada and Mexico alone. Canada, Mexico, and the Caribbean Basin Initiative (CBI) countries accounted for 50 percent ofthe total textile exports in 1996.

In 1996, U.S. exports increased by 8.6 percent over the previous year to $7.8 billion. The major export markets for the U.S. textile industry were, in order of decreasing export volumes, Canada, Mexico, United Kingdom, Japan, Hong Kong, Dominican Republic, Germany, Belgium, Saudi Arabia, and South Korea. Between 1995 and 1996, exports to all ofthese markets grew. Exports to Canada increased by 10 percent to $2.1 billion, to the European Union by 2 percent to $1.1 billion, to the Caribbean Basin Initiative (CBI) countries by 13 percent to $622 million, and to Japan by 8 percent to $299 million. Exports to Mexico increased by 28 percent to $1.2 billion (ATMI, 1997b).

Yarn, fabric, and made-ups (excluding apparel) imports into the United States also have been steadily increasing since 1978. In 1995, the major sources of imports into the U.S. were Canada, China, Pakistan, India, Mexico, Taiwan, South Korea, Thailand, Indonesia, and Japan. Although both exports and imports have risen, the textile trade deficit has widened. In 1996, the U.S. textile trade deficit fell,to $2.4 billion (ATMI, 1997b).

Sector Notebook Project 1 1 September 1997

intentionally left blank.

), Textile Industry Industrial Process Description

ni. INDUSTRIAL PROCESS DESCRIPTION

This section describes the major industrial processes in the textile industry, including the materials and equipment used and the processes employed. The section is designed for those interested in gaining a general understanding of the industry, and for those interested in the interrelationship between the industrial process and the topics described in subsequent sections of this profile -- pollutant outputs, pollution prevention opportunities, and Federal regulations. This section does not attempt to replicate published engineering information that is available for this industry. Refer to Section IX for a list of reference documents that are available. Note also that Section V, Pollution Prevention Opportunities, provides additional information on trade-offs associated with the industrial processes discussed in this section.

This section describes commonly used production processes, associated raw materials, the byproducts produced or released, and the materials either recycled or transferred off-site. This discussion identifies where in each process wastes may be produced. This section concludes with a description of the potential fate (via air, water, and soil pathways) of process-specific waste products.

1II.A. Industrial Processes in the Textile Industry

Much ofthe following sectionis based upon “BestManagementPracticesfor Pollution Prevention in the Textile Industry. ” published by the US. EPA Office of Research and Development. Additional references are cited in the text.

The textile industry is comprised of a diverse, fragmented group of establishments that produce andor process textile-related products (fiber, yarn, fabric) for further processing into apparel, home furnishings, and industrial goods. Textile establishments receive and prepare fibers; transform fibers into yam, thread, or webbing; convert the yarn into fabric or related products; and dye and fmish these materials at various stages ofproduction. The process of converting raw fibers into f ~ s h e d apparel and nonapparel textile products is complex; thus, most textile mills specialize. Little overlap occurs between hitting and weaving, or among production of manmade, cotton, and wool fabrics. The primary focus ofthis section is on weaving and knitting operations, with a brief mention of processes used to make carpets.

In its broadest sense, the textile industry includes the production of yam, fabric, and f ~ s h e d goods. This section focuses on the following four production stages, with a brief discussion of the fabrication of non-apparel goods:


Textile Industry Industrial Process Description

1) yarn formation 2) fabric formation 3) wet processing 4) fabrication

These stages are highlighted in the process flow chart shown in Figure 2 and are discussed in more detail in the following sections.

Figure 2: Typical Textile Processing Flow Chart Manmade

filament fibcrs Msnmadc Raw wool, cotton

stmlc fibers

Rbr Reparam

YARN FORMATION

. FABRIC FORMATION

Printing

Finishing

Cvninp

FABRICATION

Finished goods

Source: ATMI, Comments on draf? ofthis document, 1997b.



III.A.l. Yarn Formation

Textile fibers are converted into yam by grouping and twisting operations used to bind them together. Although most textile fibers are processed using spinning operations, the processes leading to spinning vary depending on whether the fibers are natural or manmade. Figure 3 shows the different steps used to form yarn. Note that some of these steps may be optional depending on the type of yarn and spinning equipment used. Natural fibers, known as staple when harvested, include animal and plant fibers, such as cotton and wool. These fibers must go through a series of preparation steps before they can be spun into yarn, including opening, blending, carding, combing, and drafting.

Figure 3: Yarn Formation Processes

Manmado Mnnmadr Nalursl fibers nirmentnbrra btaple fibers

Clsaning

Fabrlc larmnlion

Blending

Fabric form.llan

Source: ATMI, 1997.



Manmade fibers may be processed into fdament yarn or staple-length fibers (similar in length to natural fibers) so that they can be spun. Filament yam may be used directly or following further shaping and texturizing. The main steps used for processing natural and manmade fibers into yam are below.

Natural Fibers

Yarn formation can be performed once textile fibers are uniform and have cohesive surfaces. To achieve this, natural fibers are frst cleaned to remove impurities and are then subjected to a series of brushing and drawing steps designed to soften and align the fibers. The following describes the main steps used for processing wool and cotton. Although equipment used for cotton is designed somewhat differently from that used for wool, the machinery operates in essentially the same fashion.

Opening/Blending. Opening of bales sometimes occurs in conjunction with the blending of fibers. Suppliers deliver natural fibers to the spinning mill in compressed bales. The fibers must be sorted based on grade, cleaned to remove particles of dirt, twigs, and leaves, and blended with fibers from different bales to improve the consistency of the fiber mix. Sorting and cleaning is performed in machines known as openers. The opener consists of a rotating cylinder equipped with spiked teeth or a set of toothed bars. These teeth pull the unbaled fibers apart, fluffing them while loosening impurities. Because the feed for the opener comes from multiple bales, the opener blends the fibers as it cleans and opens them.

Carding. Tufts of fiber are conveyed by air stream to a carding machine, which transports the fibers over a belt equipped with wire needles. A series of rotating brushes rests on top of the belt. The different rotation speeds of the belt and the brushes cause the fibers to tease out and align into thin, parallel sheets. Many shorter fibers, which would weaken the yam, are separated out and removed. A further objective of carding is to better align the fibers to prepare them for spinning. The sheet of carded fibers is removed through a funnel into a loose ropelike strand called a sliver. Opening, blending, and carding are sometimes performed in integrated carders.that accept raw fiber and output carded sliver..

Combing. Combing is similar to carding except that the brushes and needles are finer and more closely spaced. Several card slivers are fed to the combing machine and removed as a fmer, cleaner, and more aligned comb sliver. In the wool system, combed sliver is used to make worsted yam, whereas carded sliver is used for woolen yam. In the cotton system, the term combed cotton applies to the yam made from combed sliver. Worsted wool and combed cotton yarns are finer (smaller) than yam that has not been'combed because of the higher degree of fiber alignment and fiuther removal of short fibers.



Drawing. Several slivers are combined into a continuous, ropelike strand and fed to a machine kno'wn as a drawing frame (Wingate, 1979). The drawing fra'me contains several sets of rollers that rotate at successively faster speeds. As the slivers pass through, they are further drawn out and lengthened, to the point where they may be five to six times as long as they were originally. During drawing, slivers fromdifferent types offibers (e.g., cotton and.polyester) may be combined to form blends. Once a sliver has been drawn, it is termed a roving.

Drafring. Drafting is a process that uses a frame to stretch the yam further. This process imparts a slight twist as it removes the yam and winds it onto a rotating spindle. The yarn, now termed a roving in ring spinning operations, is made up ofa loose assemblage offibers drawn into a single strand and is about eight times the length and one-eighth the diameter of the sliver, or approximately as wide as a pencil (Wingate, 1979). Following drafting, the rovings may be blended with other fibers before being processed into woven, knitted, or nonwoven textiles.

Spinning. 'The fibers are now spun together into either spun yams or filament yams. Filament yams are made from continuous h e strands of manmade fiber (e.g. not staple length fibers). Spun yarns are composed of overlapping staple length fibers that are bound together by twist. Methods used to produce spun yams, rather than filament yams, are discussed in this section. The rovings produced in the drafting step are mounted onto the spinning frame, where they are set for spinning. The yarn is first fed through another set of drawing or delivery rollers, which lengthen and stretch it still further. It is then fed onto a high-speed spindle by a yarn guide that travels up and down the spindle. The difference in speed of travel between the guide and the spindle determines the amount of twist imparted to the yarn. .The yarn is collected on a bobbin.

In ring spinning, the sliver is fed from delivery rollers through a traveler, or wire loop, located on a ring. The rotation of the spindle around the ring adds twist to the yam. This is illustrated in Figure 4(1). Another method, shown in Figure 4(2), is open-end spinning, which accounts for more than 50 percent ofspinning equipment used(ATMI, 1997b). In this method, sliver passes through rollers into a rotating funnel-shaped rotor. The sliver hits the inside of the rotor and rebounds to the lefi side of the rotor, causing the sliver to twist. Open-end spinning does not use rotating spindles since the yarn is twisted during passage through the rotor,



Figure 4: Comparison of Open-End and Ring Spinning Methods

Delivery Rollers -

Slivei

Source: B.P. Corbman, Textiles: Fiber to Fabric, McGraw-Hill,' Inc., 1975.

Yam spinning is basically an extension of the preparation steps described above for natural fibers. Additional twisting of the yarn may occur, or multiple yams may be twisted together to form plied yarns. Plying takes place on a machine similar to a spinning frame. Two or more yarns pass through a pair ofrollers and onto a rotating spindle. The yarn guide positions the yarn onto the spindle and assists in applying twist. Plied yarns may be plied again to form thicker cords, ropes, and cables.

Manmade Fibers

Although not classified under SIC 22, manmade fiber production is briefly discussed in the following paragraphs to describe the upstream processing of textiles. Manmade fibers include 1) cellulosic fibers, such as rayon and acetate, which are created by reacting chemicals with wood pulp; and 2 ) synthetic fibers, such as polyester and nylon, which are synthesized from



organic chemicals. Since manmade fibers are synthesized From organic chemicals, yam formation ofmanmade fibers does not involve the extensive cleaning and combing procedures associated with natural fibers. Manmade fibers, both synthetic and cellulosic, are manufactured using spinning processes that simulate or resemble the manufacture of silk. Spinning, in terms ofmanmade fiber production, is the process offorming fibers by forcing a liquid through a small opening beyond which the extruded liquid solidifies to form a continuous filament. Following spinning, the manmade fibers are drawn, or stretched, to align the polymer molecules and strengthen the filament. Manmade filaments may then be texturized or otherwise treated to simulate physical characteristics of spun natural fibers. Texturizing is often used to curl or crimp straight rod-like filament fibers to simulate the appearance, structure, and feel of natural fibers. (For more information on the synthesis ofmanmade fibers, refer to the EPA Industrial Sector Notebook on Plastic Resins and Manmade Fibers.)

Spun yarns are created using manmade fibers that have been cut into staple- length fibers. Staple-length fibers are then used to process fibers on wool or cotton-system machinery. Methods for making 'spun yam from manmade fibers are similar to those used for natural fibers. Some fibers are processed as tow, or bundles of staple fibers.

Fibers can also be produced as filament yam, which consists of filament strands twisted together slightly. In mills, filament fibers are wound onto bobbins and placed on a twisting machine to make yam. Filament yams may be used directly to make fabric or further twisted to the desired consistency. Manmade filaments often require additional drawing and are processed in an integrated drawinghwisting machine. Manmade filaments are typically texturized using mechanical or chemical treatments to impart characteristics similar to those of yams made from natural fibers.

-

III.A.2. Fabric Formation

The major methods for fabric manufacture are weaving and knitting. Figure 5 shows fabric formation processes for flat fabrics, such as sheets and apparel. Weaving, or interlacing yarns, is the most common process used to create fabrics. Weaving mills classified as broadwoven mills consume the largest portion of textile fiber and produce the raw textile material from which most textile products are made. Narrow wovens, nonwovens, and rope are also produced primarily for use in industrial applications. Narrow wovens include fabrics less than 12 inches in width, and nonwovens include fabrics bonded by mechanical, chemical, or other means. Knitting is the second most frequently used method of fabric construction. The popularity of knitting has increased in use due to the increased versatility of techniques, the adaptability of manmade fibers, and the growth in consumer demand for wrinkle-resistant, stretchable, snug-fitting fabrics. Manufacturers of knit fabrics also consume



a sizable amount oftextile fibers. Knit fabrics are generally classified as either weft knit (circular-knit goods) or warp knit (flat-knit goods). Tufting is a process used to make most carpets.

Figure 5: General Fabric Formation Processes Used for Producing Flat Fabrics

Knit t ing (wort or w a r p )

1 Fabric

Source: ATMI, 1997.

Weaving

Weaving is performed on modern looms, which contain similar parts and perform similar operations to simple hand-operated looms. Fabrics are formed &om weaving by interlacing one set of yarns with another set oriented crosswise. Figure 6 shows an example of satin weave patterns. Satin, plain, and twill weaves are the most commonly used weave patterns. In the weaving operation, the length-wise yarns that form the basic structure ofthe fabric are called the warp and the crosswise yarns are called the filling, also referred to as the weft.' While the filling yarns undergo little strain in the weaving process, warp yarns undergo much strain during weaving and must be processed to prepare them to withstand the strain (Corbman, 1975).



Figure 6: Examples of Satin Weaving Patterns

Source: B.P. Corbrnan, Texf;les: Fiber lo Fabric, McGraw-Hill, Inc., 1975.

Before weaving, warp yarns are frst wound on large spools, or cones, which are placed on a rack called a creel. The warp yarns are then unwound and passed through a sue solution (sizingklashing) before being wound onto a warp beam in a process known as beaming. The size solution forms a coating that protects the yarn against snagging or abrasion during weaving. Slashing, or applying size to the warp yarn, uses’paddry techniques in a large range called a slasher. The slasher is made up of the following: a yarn creel with very precise tension controls; a yarn guidance system; and a sizing delivery system, which usually involves tank storage and piping to the size vessels. The yam sheet is dipped one or more times in size solution and dried on hot cans or in an oven. A devise called a ‘‘lease’’ is then used to separate yams from a solid sheet back into individual ends for weaving (EPA, 1996).

Starch, the most commonprimarysizecomponent, accounts for roughlytwo- thirds of all size chemicals used in the U.S. (130 million pounds per year). Starch is used primarilyon natural fibers and in a blend with synthetic sizes for coating natural and synthetic yarns. Polyvinyl alcohol (PVA), the leading synthetic size, accounts for much ofthe remaining size consumed in the U.S. (70 million pounds per year). PVA is increasing in use since it can be recycled, unlike starch. PVA is used with polyesterlcotton yarns and pure cotton yarns either in a pure form or in blends with natural and other synthetic sizes. Other synthetic sizes contain acrylic and acrylic copolymer components. Semisynthetic sizes, such as carboxymethyl cellulose (CMC) and modified starches, are also used. Oils, waxes, and other additives are often used in



conjunction with sizing agents to increase the softness and pliability of the yarns. About I O to I5 percent of the weight of goods is added as size to cotton warp yams, compared to about 3 to 5 percent for filament synthetics.

Once size is applied, the wound beam is mounted in a loom. Shuttle looms are rapidly being replaced by shuttleless looms, which have 'the ability to weave at higher speeds and with less noise. Shuttleless looms are discussed in the next section. The operation ofa traditional shuttle loom is discussed in this section to illustrate the weaving process.

The major components ofthe loom are the warp beam, heddles, harnesses, shuttle, reed, and takeup roll (see Figure 7). In the loom, yam processing includes shedding, picking, battening, and taking up operations. These steps are discussed below.

Shedding. Shedding is the raising of the warp yams to form a shed through which the filing yarn, carried by the shuttle, can be inserted. The shed is the vertical space between the raised and unraised warp yarns. On the modern loom, simple and intricate shedding operations are performed automatically by the heddle frame, also known as a hamess. This is a rectangular frame to which a series ofwires, called heddles, are attached. The yams are passed through the eye holes of the heddles, which hang vertically from the harnesses.

The weave pattern determines which hamess controls which warp y a m , andthe number ofharnesses useddepends onthe complexityofthe weave (Corbman, 1975).

Picking. As the harnesses raise the heddles, which raise the warp yarns, the shed is created. The fdling yam in inserted through the shed by a small carrier device called a shuttle. The shuttle is normally pointed at each end to allow passage through the shed. In a traditional shuttle loom, the filling yarn is wound onto a quill, which in turn is mounted in the shuttle. The filling yam emerges through a hole in the shuttle as it moves across the loom. A single crossing of the shuttle from one side of the loom to the other is known as a pick. As the shuttle moves back and forth across the shed, it weaves an edge, or selvage, on each side of the fabric to prevent the fabric from raveling.

Battening. As the shuttle moves across the loom laying down the fll yam, it also passes through openings in another frame called a reed (which resembles a comb). With each picking operation, the reed presses or battemeach filling yarn against the portion of the fabric that has already been formed. Conventional shuttle looms can operate at speeds of about 150 to 160 picks per minute.



Taking up and letting off: With each weaving operation, the newly constructed fabric must be wound on a cloth beam. This process is called taking up. At the same time, the warp yams must be let off or released from the warp beams (Corbman, 1975).

Figure 7: Typical Shuttle Loom

/o

CLOTH

WARP BEA.U FILLING YARN CLOTH ROLL

Source: I.B. Wingate, Fairchild's Dictionary of Textiles. Fairchild Publications, Inc., 1979.

Shuttleless Looms

Because the shuttle can cause yarns to splinter and catch, several types of shuttleless looms have been developed. These operate at higher speeds and reduced noise levels. By the end of 1989, shuttleless looms represented 54 percent ofall looms installed, up from 15 percent in 1980. Shuttleless looms use different techniques to transport cut pieces of fill yam across the shed, as opposed to the continuous yam used in shuttle looms.

Some ofthe common shuttleless looms include water-jet looms, air-jet looms, rapier looms, and projectile looms. Water-jet looms transport the fill yam in a high-speed jet of water and can achieve speeds of 400 to 600 picks per minute. Water jets can handle a wide variety of fiber and yam types and are widely used for apparel fabrics. Air-jet looms use a blast of air to move the fill yarn and can operate at speeds of 800 to 1000 picks per minute. Rapier looms use two thin wire rods to carry the fill yam and can operate at a speed of 5 I O picks per minute. Rapiers are used mostly for spun yarns to make cotton and wooledworsted fabrics. In a double rapier loom, two rods move kom each side and meet in the middle. The fill yam is carried *om the rod on



the fill side and handed offto the rod on the fmish side ofthe loom. Projectile looms use a projectile to carry the fill yarn across the weave.

Shuttleless looms have been replacing the traditional fly-shuttle loom in recent years. Air looms, although limited in the types offilling yarns they canhandle, are increasing in commercial use. The operation of an air jet loom is shown in Figure 8. As shown in the figure, yarn is drawn from the yam package (1) by the measuring wheel and drive roller arrangement (2). Between the yarn package and the measuring wheel is a tube through which an air current flows in opposite direction to the yam. This maintains a straight even feed of yam. The yam then forms a loop (3) which shortens as the pick penetrates further into the shed. The main jet (4) is the major projecting force for the yarn, although supplementary jets (5) are activated to prevent the pick fiom buckling.

Figure 8: Typical Air Jet Loom

Source: A. Ormerod, Modem Preparation and Weaving Machinery. Butlerworihs, 1983

Kniffing

Knitted fabrics may be constructed by using hooked needles to interlock one or more sets ofyams through a set of loops. The loops may be either loosely or closely constructed, depending on the purpose of the fabric. Knitted fabrics can be used for hosiery, underwear, sweaters, slacks, suits, coats, rugs, and other home furnishings. Knitting is performed using either weft or warp processes, depicted in Figure 9. In weft (or filling) hitting, one yam is carried back and forth and under needles to form a fabric. Yams run horizontally in the fabric, and connections between loops are horizontal. In


warp knitting, a warp beam is set into the knitting machine. Yarns are interlocked to form the fabric, and the yarns run vertically while the connections are on the diagonal. Several'different types of machinery are used in both we!? and warp knitting.

Figure 9: Comparison Between Warp and Weft Knitting Methods

(a) Weft

A

Source: D.J. Spencer, Knitting Technologv. Pergamon Press, 1989

Weft knitting. Weft knitting uses one continuous yam to form courses, or rows of loops, across a fabric. There are three hndamental stitches in weft knitting: plain-knit, purl, and rib. On a machine, the individual yam is fed to one or more needles at a time. Weft knitting machines can produce both flat and circular fabric. Circular machines produce mainly yardage but may also produce sweater bodies, pantyhose, and socks. Flatbed machines knit full garments and operate at much slower speeds. The simplest, most common filing knit fabric is single jersey. Double knits are made on machines with two sets of needles. All hosiery is produced as a filling knit process.

Warp Knitting. Warp knitting represents the fastest method ofproducing fabric from yarns. Warp knitting differs from weft knitting in that each needle loops its own thread. The needles produce parallel rows of loops simultaneously that are interlocked in a zigzag pattern. Fabric is produced in sheet or flat form using one or more sets ofwarp yams. The yarns are fed from warp beams to a row of needles extending across the width of



the machine (Figure 9b). Two common types of warp knitting madines are the Tricot andRaschelmaches. Rascbel machines are useful because they can process all yarn types in all forms (filament, staple, combed, carded, etc.). Warp knitting can also be used to make pile fabrics often used for upholstery.

Tufting

Tufting is a process used to create carpets, blankets, and upholstery. Tufting is done by inserting additional yams into a ground fabric ofdesired weight and yam content to create a pde fabric. The substrate fabric can range from a thin backing to heavy burlap-type material and may be woven, knitted, or web. In modern tufting machines, a set ofholiow needles carries the yam from a series of spools held in a creel and inserts the yarn through the substrate cloth. As each needle penetrates the cloth, a hook on the underside forms a loop by catching and holding the yarn. The needle is withdrawn and moves forward, much like a sewing machine needle. Patterns may be formed by varying the height of the tuft loops. To make cut-loop pile, a knife is attached to the hook and the loops are cut as the needles are retracted. Well over 90 percent of broadloom carpeting is made by tufting, and modem machines can stitch at rates ofover 800 stitches per minute, producing some 650 square yards of broadloom per hour.

lII.A.3. Wet Processing

Woven and knit fabrics cannot be processed into apparel and other f ~ h e d goods until the fabrics have passed through several water-intensive wet processing stages. Wet processing enhances the appearance, durability, and serviceability of fabrics by converting undyed and unfinished goods, known as gray or greige (pronounced gri[zh]) goods, into finished consumers’ goods. Also collectively known as fmishing, wet processing has been broken down into four stages in this section for simplification: fabric preparation, dyeing, printing, and finishing. These stages, shown in Figure 10, involve treating gray goods with chemical baths and often require additional washing, rinsing, and drying steps. Note that some o f these steps may be optional depending on the style of fabric being manufactured.



Figure 10: Typical Wet Processing Steps for Fabrics Unfinished fabric or "greige goods"

100% Synthetics Cotton + Cotton Blends + + 1

Singeing * *

I Scouring ' I +

Bleaching w Mercerizing

PREPARATION

6 Printing I 1 DYEING AND/OR PRI"G

I I

I

Heat set Synthetics and blends only)

Finished fabric

Source: ATMI, 1997



In terms ofwaste generation and environinental impacts, wet processing is the most significant textile operation. Methods used vary greatly depending on end-products and applications, site-specific manufacturing practices, and fiber type. Natural fibers typically require more processing steps than manmade fibers. For most wool products and some manmade and cotton products, the yarn is dyed before weaving; thus, the pattern is woven into the fabric. Processing methods may also differ based on the fmlproperties desired, such as tensile strength, flexibility, uniformity, and luster (Snowden-Swan, 1995).

Most manufactured textiles are shipped from textile mills to commission dyeing and finishing shops for wet processing, although some fvms have integrated wet processing into their operations. A wide range of'equipment is used foi textile dyeing and finishing (EPA, 1996). Much of the waste generated from the industry is produced during the wet processing stages; Relativelylargevolumesofwastewater aregenerated, containingawiderange of contaminants that must be treated prior to disposal. Significant quantities ofenergy are spent heating and cooling chemical baths and drying fabrics and yarns (Snowden-Swan, 1995).

Fabric Preparation

Most fabric that is dyed, printed, or f ~ s h e d must fvst be prepared, with the exception of denim and certain knit styles. Preparation, also known as pretreatment, consists ofa series ofvarious treatment and rinsing steps critical to obtaining good results in subsequent textile finishing processes. . In preparation, the mill removes natural impurities or processing chemicals that interfere with dyeing, printing, and finishing. Typical preparation treatments include desizing, scouring, and bleaching. Preparation steps can also include processes, such as singeing and mercerizing, designed to chemically or physically alter the fabric. For instance, the mercerizing stage chemically treats the fabric to increase fiber strength and dye affinity, or ability to pick up dyes. This, in turn, increases the longevity of fabric finishes applied during fmishing. Many ofthe pollutants from preparation result from the removal of previously applied processing chemicals and agricultural residues. , These chemical residues can be passed on to subsequent stages with improper preparation.

Most mills can use the same preparation equipment for the entire range of products they produce. In most cases, facilities favor continuous rather than batch preparation processes for economic and pollution control reasons. A number ofmills, however, prepare goods, particularlyknits, batchwise ondye- ing machines to simplify scheduling and handling. Sometimes, facilities operate batchwise to reduce high capital costs required for high productivity and the complexity of storing and tracking goods through continuous wet processing operations.



Because preparation is relatively uniform across most of a mill's production, preparation is usually the highest-volume process in a mill and hence an important area for pollution prevention. Iffabrics contained no contamination upon arrival for wet processing, preparation processes would be unnecessary, eliminating about half the pollution outputs from wet processing and a significant amount of wastewater. The primary pollutants fiom preparation is wastewater containing alkalinity, BOD, COD, and relatively small amounts of other contaminants such. as metals and surfactants. There are many preparation techniques, some of which are described below.

Singeing. If a fabric is to have a smooth f i s h , singeing is essential. Singeing is a dry process used on woven goods that removes fibers protruding from yarns or fabrics. These are burned off by passing the fibers over a flame or heated copperplates. Singeing improves the surface appearance ofwoven goods and reduces pilling. It is especiallyuseful for fabrics that are to be printed or where a smooth finish is desired. Pollutant outputs associated with singeing include relatively small amounts of exhaust gases from the burners.

Desiring. Desizing is an important preparation step used to remove size materials applied prior to weaving. Manmade fibers are generally sized with water-soluble sizes that are easily removed by a hot-water wash or in the scouring process. Natural fibers such as cotton are most often sized with water-insoluble starches or mixtures of starch and other materials. Enzymes areused to break these starches into water-soluble sugars, which are then removed by washing before the cloth is scoured. Removing starches before scouring is necessary because they can react and cause color changes when exposed to sodium hydroxide in scouring.

Scouring. Scouring is a cleaning process that removes impurities from fibers, yarns, or cloth through washing. Alkaline solutions are typically used for scouring; however, in some cases solvent solutions may also be used. Scouring uses alkali, typically s o d i d hydroxide, to break down natural oils and surfactants and to emulsify and suspend remaining impurities in the scouring bath. The specific scouring procedures, chemicals, temperature, and time vary with the type of fiber, yarn, and cloth construction. Impurities may include lubricants, dirt and other natural materials, water-soluble sizes, antistatic agents, and residual tints used for yarn identification. Typically, scouring wastes contribute a large portion of biological oxygen demand (BOD) loads from preparation processes (NC DEHNR, 1986). Desizing and scouring operations are often combined (ATMI, 1997).

Bleaching. Bleaching is a chemical process that eliminates unwanted colored matter from fibers, yams, or cloth. Bleaching decolorizes colored impurities that are not removed by scouring and prepares the cloth for



further fmishing processes such as dyeing or printing. Several different types ofchemicals are used as bleaching agents, and selection depends on the type of fiber present in the yam, cloth, or f ~ s h e d product and the subsequent finishing that the product will receive. The most common bleaching agents includehydrogen peroxide, sodiumhypochlorite, sodium chlorite, and sulfur dioxide gas. Hydrogen peroxide is by far the most commonlyused bleaching agent for cotton and cotton blends, accounting for over 90 percent ofthe bleach used in textile operations, and is typically used with caustic solutions. Bleaching contributes less than 5 percent of the total textile mill BOD load (NC DEHNR, 1986).

The bleaching process involves several steps: 1)The cloth is saturated with the bleaching agent, activator, stabilizer, and other necessary chemicals; 2) the temperature is raised to the recommended level for that particular fiber or blend and held for the amount of time needed to complete the bleaching action; and 3) the cloth is thoroughly washed and dried. Peroxide bleaching can be responsible for wastewater with high pH levels. Because peroxide bleaching typically produces wastewater with few contaminants, water conservation and chemical handling issues are the primary pollution concerns.

Mercerizing. Mercerization is a continuous chemical process used for cotton and cottodpolyester goods to increase dyeability, luster, and appearance. This process, which is carried out at room temperature, causes the flat, twisted ribbon-like cotton fiber to swell into a round shape and to contract in length. This causes the fiber to become more lustrous than the original fiber, increase in strength by as much as 20 percent, and increase its affinity for dyes. Mercerizing typically follows singeing and may either precede or follow bleaching (Corbman, 1975).

During mercerizing, the fabric is passed through a cold 15 to 20 percent solution of caustic soda and then stretched out on a tenter frame where hot-water sprays remove most of the caustic solution (Corbman, 1975). After treatment, the caustic is removed by several washes under tension, Remaining caustic may he neutralized with a cold acid treatment followed by several more rinses to remove the acid. Wastewater from mercerizing cancontain substantial amounts ofhigh pH alkali, accounting for about 20 percent of the weight of goods.

Dyeing

Dyeing operations are used at.various stages ofproduction to add color and intricacy to textiles and increase product value. Most dyeing is performed either by the fmishing division ofvertically integrated textile companies, or by specialty dyehouses. Specialty dyehouses operate either on a commission basis or purchase greige goods and finish them before selling them to apparel



and other product manufacturers. Textiles are dyed using a wide range of dyestuffs, techniques, and equipment. Dyes used by the textile industry are largely synthetic; typically derived from coal tar and petroleum-based intermediates. Dyes are sold as powders, granules, pastes, and liquid dis- persions, with concentrations of active ingredients ranging typically from 20 to 80 percent.

Methods of Dyeing

\ Dyeing can be performed using continuous or batch processes. In batch dyeing, a certain amount oftextile substrate, usually 100 to 1,000 kilograms, is loaded into a dyeing machine and brought to equilibrium, or near equilibrium, with a solution containing the dye. Because the dyes have an a f f i t y for the fibers, the dye molecules leave the dye solution and enter the fibers over a period of minutes to hours, depending'on the type of dye and fabric used. Auxiliary chemicals and controlled dyebath conditions (mainly temperature) accelerate and optimize the action. The dye is fvted in the fiber using heat and/or chemicals, and the tinted textile substrate is washed to remove unfuced dyes and chemicals. Commonmethods ofbatch, or exhaust, dyeing include beam, beck, jet, and jig processing. Pad dyeing can be performed by either batch or continuous processes.

In continuous dyeing processes, textiles are fed continuously into a dye range at speeds usually between 50 and 250 meters per minute. Continuous dyeing accounts for about 60 percent oftotal yardage ofproduct dyed inthe industry (Snowden-Swan, 1995). To be economical, this may require the dyer to process 10,000 meters oftextiles or more per color, although specialtyranges are now being designed to run as little as 2,000 meters economically. Continuous dyeing processes typically consist of dye application, dye fixation with chemicals or heat, and washing. Dye futation is a measure ofthe amount of the percentage of dye in a bath that will fuc to the fibers of the textile material. Dye futation on the fiber occurs much more rapidly in continuous dying than in hatch dyeing.

Each dyeing process requires different amounts of dye per unit of fabric to be dyed. This is significant since color and salts in wastewater from spent dyes are often a pollution concern for textile facilities. In addition, less dye used results in energy conservationand chemical savings. The amounts ofdye used depends on the dye is exhausted from the dyebaths which determines the required dyebath ratio. The dyebath ratio is the ratio of the units of dye required per unit of fabric and typically ranges from 5 to 50 depending on the type of dye, dyeing system, and affmity of the dyes for the fibers.

Dyeing processes may take place at any ofseveral stages ofthe manufacturing process (fibers, yarn, piece-dyeing). Stock dyeing is used to dye fibers. Top dyeing is used to dye combed wool sliver. Yam dyeing and piece dyeing,



done after the yam has been constructed into fabric, are discussed in more detail below.

Yarn Dyeing. Yarndyeing is used to create interesting checks, stripes, and plaids withdifferent-colored yarns in the weaving process. In yam dyeing, dyestuff penetrates the fibers in the core of the yarn.

Some methods of yam dyeing are stock, package, and' skein dyeing. Stock dyeing dyes fiber using perforated tubes. In package dyeing (Figure 1 I), spools ofyarnare stackedonperforatedrods inarackandimmersed

' in a tank where dye is then forced outward from the rods under pressure. The dye is then pressured back through the packages toward the center to hlly penetrate the entire yarn. Most carded and combed cotton used for knitted outerwear is package-dyed. In skein dyeing, yam is loosely coiled on a reel and then dyed. The coils, or skeins, are hung over a rung and immersed in a dyebath (Corhman, 1975). Skein-dyed yam is used for bulky acrylic and wool yams. Typical capacity for package dyeing equipment is 1,210 pounds (550 kg) and for skein dyeing equipment is 220 pounds (100 kg).

Piece Dyeing. Most dyed fabric is piece-dyed since this method gives the manufacturer maximum inventory flexibility to meet color demands as fashion changes. In terms of overall volume, the largest amount ofdyeing is performed using beck and jig equipment (Figure 1 I). Beck dyeing is a versatile, continuous process used to dye long yards of fabric. About 1,980 pounds (900 kg) of fabric can be dyed on beck equipment at a time. The fabric is passed in rope form through the dyebath. The rope moves over a rail onto a reel which immerses it into the dye and then draws the fabric up and forward to the front of the machine. This process is repeated as long as necessary to dye the material uniformly to the desired color intensity. Jig dyeing uses the same procedure of beck dyeing, however, the fabric is held on rollers at full width rather than in rope form as it is passed through the dyebath (Corbman, 1975). This reduces fabric tendencyto crack or crease. Jig dyeing equipment canhandle 550 pounds (250 kg) of fabric.

Other piece dyeing methods includejet dyeing and pad dyeing. Fabric can be jet-dyed (at up to 1,100 pounds (500 kg)) by placing it in a heated tube or column where jets of dye solution are forced through it at high pressures. The dye is continually recirculated as the fabric is moved along the tube. Pad dyeing, like jig dyeing, dyes the fabric at full width. The fabric is passed through a trough containing dye and then between two heavy rollers which force the dye into the cloth and squeeze out the excess (Corbman, 1975). Figure 11 illustrates the beck, jig, and jet methods for dyeing.

September 1997 Sector Notebook Project 32 .


Figure 11: Common Dyeing Methods

Package Dyeing

Jet Dyeing

Oyc liquor is pumped. thus mnaponing fabnc through the dying vcnmci tube

Dye Liquor

Jig Dyeing (end view)

F Dyc liquor

Bame

Beck Dyeing (end view)

Idler

Winch

Dye Liquor

Added

Source: Best Managemenr Practices for Pollurion Prevenrion in the Textile Industry. EPA, Office of Research and Development, 1995.


Textile Industry Industrial Process Descrjption

Types of Dyes

Dyes may be classified in several ways (e.g., according to chemical constitution, application class, end-use). The primary classification of dyes is based on the fibers to which they can be applied and the chemical nature of each dye. Table 6 lists the major dye classes, fixation rates, and the types of fibers for which they have an affinity. Factors that companies consider when selecting a dye include the type of fibers being dyed, desired shade, dyeing uniformity, and fastness (desired stability or resistance of stock or colorants to influences such as light,,alkali, etc) (FFTA, 1991).

Most commonly in use today are the reactive and direct types for cotton dyeing, and disperse types for polyester dyeing. Reactive dyes react with fiber molecules to form chemical bonds. Direct dyes can color fabric directly with one operation and without the aid of an affixing agent. Direct dyes are the simplest dyes to apply and the cheapest in their initial and application costs although there are tradeoffs in the dyes’ shade range and wetfastness (Corbman, 1975). Direct and reactive dyes have a fvtation rate of 90 to 95 percent and 60 to 90 percent, respectively. A variety of auxiliary chemicals may be used during dyeing to assist in dye absorption and fixation into the fibers. Disperse dyes, with futation rates of 80 to 90 percent, require additional factors, such as dye carriers, pressure, and heat, to penetrate synthetic fibers (Snowden-Swan, 1995; ATMI, 1997). Disperse dyes are dispersed in water where the dyes are dissolved into fibers. Vat dyes, such as indigo, are also commonly used for cotton and other cellulosic fibers.



I

J-F W 2



Printing

Fabrics are often printed with color and patterns using a variety oftechniques and machine types. Of the numerousprinting techniques, the most common is rotary screen. However, other methods, such as direct, discharge, resist, flat screen (semicontinuous), and roller printing are often used commercially. Pigments are used for about 75 to 85 percent ofall printing operations, do not require washing steps, and generate little waste (Snowden-Swan, 1995). Compared to dyes, pigments are typically insoluble and have no affiity for the fibers. Resin binders are typically used to attach pigments to substrates. Solvents are used as vehicles for transporting the pigment and resin mixture to the substrate. The solvents then evaporate leaving a hard opaque coating. The major types of printing are described below.

Rofuiy screen prinfing. Rotary screen printing uses seamless cylindrical screens made of metal foil. The machine uses a rotary screen for each color. As the fabric is fed under uniform tension into the printer section of the machine, its back is usually coated with an adhesive which causes it to adhere to a conveyor printing blanket. Some machines use other methods for gripping the fabric. The fabric passes under the rotating screen through which the printing paste is automatically pumped from pressure tanks. A squeegee in each rotary screen forces the paste through the screen onto the fabric as it moves along (Corbman, 1975). The fabric then passes to a drying oven.

Direct printing. In direct printing, a large cylindrical roller picks up the fabric, and smaller rollers containing the color are brought into contact with the cloth. The smaller rollers are etched with the design, and the number of rollers reflects the number of colors. Each smaller roller is supplied with color by a hrnisher roller, which rotates in the color trough, picks up color, and deposits it on the applicator